The maturity of the birch tree had caused strips of silver bark to peel back. She could see the tree’s insect inhabitants scurrying out of sight of her prying eyes, except at one particular spot.

An area they obviously had no desire to leave.

At first she assumed it was blood, rich in nutrients and a veritable feast, but closer inspection suggested something more. Rhona used tweezers to extract the material.

A hair, blood-soaked but probably blond in colour, was attached to what definitely looked like scalp tissue.

So someone’s head had hit the tree trunk with enough force to cause a scalp wound or maybe even a skull fracture?

Even minor cuts on the head often bled heavily because the face and scalp had many blood vessels close to the surface of the skin. Judging by the blood on surrounding soil, this one had too. From the compressed vegetation, it appeared that the injured person had been sufficiently traumatized to end up on the ground.

So maybe more than a scalp abrasion?

The average thickness of a man’s skull was 6.5 millimetres. Women’s skulls were thicker at an average of 7.1, although in back-to-front measurement and width, male skulls won the size game. She couldn’t tell here if the material in her hand belonged to a male or a female, but she could say it had come from a human.

Having drawn the tarpaulin back into place, Rhona gathered her samples. Realizing she was finished with whatever she’d been doing, Blaze sprang up to lead her back to the camp. But Rhona wasn’t ready to go there yet.

Whoever had been injured here had either walked out, aided or unaided, or else they’d been carried. Either way they had to have left tracks. Tracks she might be able to follow. But if not her, then certainly the dog that had brought her here in the first place.

10

McNab stared at the big bloke across the table from him. Beside him, DS Clark maintained a calm expression, although he knew her well enough to know her blood was at boiling point.

‘Fucking pair of tits ordering me about.’

It wasn’t clear if the punk’s utterance referred to the female detective before him or the girl whose nose he’d ‘allegedly’ broken.

‘Tell us again what happened,’ McNab said.

‘Just like she told you. She fell.’

‘She fell just like that?’

‘Tripped over the fucking dog. Silly bitch. Banged into the door.’

McNab had often wondered what it was that doors and door frames had against the female population of Glasgow. They seemed to take a perverse delight in banging into them, with no provocation whatsoever.

‘Jess tells a different story.’

The smug look shifted a little, then resettled, fear quickly dispensed with.

‘Jess would never—’

‘Never say never,’ McNab offered with a knowing smile.